This application for a five-year renewal (years 16-20) of an Institutional Training Grant for the Clinical Trials Training Program (CTTP) in Vision Research is aimed at multi-disciplinary training in the design and conduct of clinical trials with an emphasis on eye trials. The goal is to develop creative and independent investigators, capable of assuming leadership roles in the design and conduct of clinical trials, and of carrying out methodologic research in relation to trials. The Program is based in the Department of Epidemiology, but benefits from close ties with the Departments of Biostatistics, International Health and Ophthalmology, other Departments at the Johns Hopkins Medical Institutions, and with other organizations external to Hopkins, such as the Veteran's Administration Cooperative Studies Program. Both pre- and postdoctoral research training will be provided via formal course work and practical "hands-on experience" in trials. This combination is intended to attract both new potential trialists as well as individuals already involved in trials needing more training, or wishing to refocus their efforts on vision research. All trainees will be enrolled in degree programs in Epidemiology, Biostatistics, or International Health in the Bloomberg School of Public Health, or the Department of Ophthalmology in the School of Medicine, and will participate in (1) a structured schedule of didactic course work, (2) journal club, seminar series, and research-in-progress meetings (3) "hands-on" experience in ongoing clinical trials at various stages of development, (4) the teaching program in the Department of Epidemiology, and (5) a thesis research project. Pre-doctoral training is aimed at persons who have undergraduate or masters level graduate degrees, and post-doctoral training at persons with an MD or PhD in health-related fields who are interested in becoming clinical trialists. At full capacity, the Program would have 8 trainees (6 pre-doctoral and 2 post-doctoral). Predoctoral students pursuing a PhD will require 3 to 5years to matriculate through the Program. Postdoctoral students pursuing a PhD will require 2 to 4 years depending on their credentials. Relevance: The multi-disciplinary nature of clinical trials, as well as their complexity, makes it important to produce highly trained individuals who are abreast of the issues (political and methodological) facing trialists today. Trained individuals will become leaders in their fields, trialists, methodologists, and others who will continue to evaluate new treatments and develop new methodologies, for the benefit of the public health.